basics.md

Basics

Some python inspiration:

• Comments start with #
• Indentation with tabs defines blocks

Some c++ inspiration:

• Strongly typed
• Compiled and executed as machine code

Some other inspirations:

• Things are mostly immutable by default

Main

The program start by executing a main() function:

func main()
    print("hi")

This can optionally take command-line arguments:

func main(args: string[])
    ...

Variables

The common basic types are:

Type	Meaning
i32	(32bit) signed integers
f32	(32bit) floating point numbers
string	strings ("text") of arbitrary length
bool	boolean truth values, can be true or false

Less common are other signed integers (i64, i16, i8), unsigned 8bit integers (u8), 64 bit "doubles" (f64).

Defining a variable:

# Common usage
var i = 13

# Or, more verbose
var i: i32 = 13

# i is mutable
i = 20

🔥 Variables can change values, but they can never change their type!

If the variable does not need to be mutable, use let:

let i = 13
let f = 1.25
let s = "hi"
let b = true

Basic control flow

Conditions:

if i > 10
    print("big!")
else
    print("small")
    print("...")

Basic loop:

for i in 0:5
    if i == 3
        continue
    print(i)
    if i == 1
        print("...")
# output:
# 0
# 1
# ...
# 2
# 4

Start at 0, end BEFORE 5. Respects continue and break.

Boolean logic

Boolean operators are words:

let a = true
let b = false
let c = a and b
let d = not (b or c)
if d
    ...

Funky stuff

🔥 Blocks can have a value!

Might not sound impressive, but you can write

let i = if condition
    13
else
    99

(both branches of if need to be of the same type)